The invention relates to a machine for the blow thermoforming of bottles, containers and, more generally, hollow articles, in thermoplastic material, characterized by a high output, a relatively simplified construction, limited floorspace requirements and high technological reliability. The machine according to the invention is distinguished from conventional machines by the fact that it is provided, on the same carriage which moves alternately between the blowing station and the dual-purpose station where the labels are fed and the parisons of thermoplastic material coming from the extrusion head are loaded, with two adjacent pairs of male and female mould halves, hereinafter referred to more simply as moulds, which close and open with a self-centring movement. The containers coming from the scrap-removal stations are conveyed along a single transverse discharging line. The magazines containing the labels for insertion into the thermoforming moulds are located on opposite sides of the machine in a convenient position for inspection and for periodical refilling with labels.